The potential of drug repurposing combined with reperfusion therapy in cerebral ischemic stroke: A supplementary strategy to endovascular thrombectomy

Stroke is the major cause of adult disability and the second or third leading cause of death in developed countries. The treatment options for stroke (thrombolysis or thrombectomy) are restricted to a small subset of patients with acute ischemic stroke because of the limited time for an efficacious response and the strict criteria applied to minimize the risk of cerebral hemorrhage. Attempts to develop new treatments, such as neuroprotectants, for acute ischemic stroke have been costly and time-consuming and to date have yielded disappointing results. The repurposing approved drugs known to be relatively safe, such as statins and minocycline, may provide a less costly and more rapid alternative to new drug discovery in this clinical condition. Because adequate perfusion is thought to be vital for a neuroprotectant to be effective, endovascular thrombectomy (EVT) with advanced imaging modalities offers the possibility of documenting reperfusion in occluded large cerebral vessels. An examination of established medications that possess neuroprotective characters using in a large-vessel occlusive disorder with EVT may speed the identification of new and more broadly efficacious medications for the treatment of ischemic stroke. These approaches are highlighted in this review along with a critical assessment of drug repurposing combined with reperfusion therapy as a supplementary means for halting or mitigating stroke-induced brain damage.

Thrombolysis with rhPro-UK 3 to 6 hours after embolic stroke in rat

Objectives: To investigate the thrombolysis with recombinant human prourokinase (rhPro-UK) on thromboembolic stroke in rats at different therapeutic time windows (TTW). Methods: Rats were subjected to embolic middle cerebral artery occlusion. RhPro-UK and positive control drugs rt-PA,UK were administered 3 h, 4.5 h, 6 h after inducing thromboem-bolic stroke. Neurological deficit scoring (NDS) was evaluated at 6 h and 24 h after the treatment. The lesion volume in cerebral hemispheres was measured by MRI scanning machine after 6 h of thrombolysis, and the infarct volume was measured by TTC stain, together with hemorrhagic volume quantified by a spectrophotometric assay after 24 h of thrombolysis. Results: RhPro-UK 10, 20 × 10⁴ U/kg significantly improved the NDS after cerebral thromboembolism in rats at 3 h, 4.5 h TTW, and at the 6 h TTW, the NDS was improved by 28.0% (P = 0.0690) and 29.2% (P = 0.0927) at 6 h and 24 h after rhPro-UK 20 ×10⁴ U/kg administration, respectively. RhPro-UK 10, 20 × 10⁴ U/kg significantly reduced the brain lesions measured by MRI at 3 h and 4.5 h TTW. RhPro-UK 10, 20 × 10⁴ U/kg significantly reduced the cerebral infarction measured by TTC at 3 h, 4.5 h TTW. There was no increase in cerebral hemorrhage compared with untreated group after rhPro-UK administration. Conclusions: RhPro-UK had an obvious therapeutic effect on ischemic stroke caused by thrombosis, and could be started within 4.5 h TTW with less side effects of cerebral hemorrhage than that of UK.

[Acute treatment of ischemic stroke : Current standards]

Important milestones of acute ischemic stroke (AIS) treatment were achieved in recent years. The results of two randomized controlled trials revealed that intravenous thrombolysis is efficacious for treatment of AIS patients with a symptom onset <9 h or an unknown time of symptom onset in the presence of beneficial patterns in advanced stroke imaging. These patterns comprise the evidence of salvageable tissue at risk of infarction in perfusion of computed tomography (so-called penumbral imaging) or a mismatch between the diffusion-weighted imaging (DWI) und fluid-attenuated inversion recovery (FLAIR) sequences in magnetic resonance imaging (so-called DWI-FLAIR mismatch). Another two randomized controlled trials resulted in evidence of a high effectiveness of mechanical thrombectomy using advanced imaging of selected AIS patients with a symptom onset <24 h or an unknown time window. This article provides an overview of the current study results and recommendations for the selection of imaging for evidence-based effective acute treatment of stroke patients.

Chronic kidney disease in the pathogenesis of acute ischemic stroke

Chronic kidney disease has a graded and independent inverse impact on cerebrovascular health. Both thrombotic and hemorrhagic complications are highly prevalent in chronic kidney disease patients. Growing evidence suggests that in chronic kidney disease patients, ischemic strokes are more common than hemorrhagic strokes. Chronic kidney disease is asymptomatic until an advanced stage, but mild to moderate chronic kidney disease incites various pathogenic mechanisms such as inflammation, oxidative stress, neurohormonal imbalance, formation of uremic toxins and vascular calcification which damage the endothelium and blood vessels. Cognitive dysfunction, dementia, transient infarcts, and white matter lesions are widespread in mild to moderate chronic kidney disease patients. Uremic toxins produced after chronic kidney disease can pass through the blood-brain barrier and mediate cognitive dysfunction and neurodegeneration. Furthermore, chronic kidney disease precipitates vascular risk factors that can lead to atherosclerosis, hypertension, atrial fibrillation, and diabetes. Chronic kidney disease also exacerbates stroke pathogenesis, worsens recovery outcomes, and limits the eligibility of stroke patients to receive available stroke therapeutics. This review highlights the mechanisms involved in the advancement of chronic kidney disease and its possible association with stroke.

Thrombolytic Therapy in the Current ERA: Myocardial Infarction and Beyond

Thrombolytic therapy kick-started the era of modern cardiology but in the last few decades it has been largely supplanted by primary percutaneous coronary intervention (PCI) as the go-to treatment for acute myocardial infarction. However, these agents remain important for vast populations without access to primary PCI and acute ischemic stroke. More innovative uses have recently come up for the treatment of a variety of conditions. This article summarizes the history, evidence base and current use of thrombolytics in cardiovascular disease.

Urokinase Plasminogen Activator: A Potential Thrombolytic Agent for Ischaemic Stroke

Stroke continues to be one of the leading causes of mortality and morbidity worldwide. Restoration of cerebral blood flow by recombinant plasminogen activator (rtPA) with or without mechanical thrombectomy is considered the most effective therapy for rescuing brain tissue from ischaemic damage, but this requires advanced facilities and highly skilled professionals, entailing high costs, thus in resource-limited contexts urokinase plasminogen activator (uPA) is commonly used as an alternative. This literature review summarises the existing studies relating to the potential clinical application of uPA in ischaemic stroke patients. In translational studies of ischaemic stroke, uPA has been shown to promote nerve regeneration and reduce infarct volume and neurological deficits. Clinical trials employing uPA as a thrombolytic agent have replicated these favourable outcomes and reported consistent increases in recanalisation, functional improvement and cerebral haemorrhage rates, similar to those observed with rtPA. Single-chain zymogen pro-urokinase (pro-uPA) and rtPA appear to be complementary and synergistic in their action, suggesting that their co-administration may improve the efficacy of thrombolysis without affecting the overall risk of haemorrhage. Large clinical trials examining the efficacy of uPA or the combination of pro-uPA and rtPA are desperately required to unravel whether either therapeutic approach may be a safe first-line treatment option for patients with ischaemic stroke. In light of the existing limited data, thrombolysis with uPA appears to be a potential alternative to rtPA-mediated reperfusive treatment due to its beneficial effects on the promotion of revascularisation and nerve regeneration.

Acute Ischemic Stroke in a Child Successfully Treated with Thrombolytic Therapy and Mechanical Thrombectomy

Acute ischemic stroke in the pediatric population is rare but carries lasting and often lifelong morbidity. Thrombolysis and mechanical thrombectomy are mainstays of care in adults, yet there is very little evidence for these treatments in children. We present the case of a 4-year-old boy with complex congenital heart disease, admitted 30 min after sudden onset of an aphasia and right hemiplegia, scoring 14 on the Pediatric National Institutes of Health Stroke Scale (PedNIHSS). Non-contrast brain computed tomography (CT) showed no evidence of acute ischemia. CT angiogram demonstrated a thrombus in the M1 segment of the left middle cerebral artery. Intravenous recombinant tissue plasminogen activator (rTPA) was infused 3.5 h after onset of symptoms. An improvement was observed in the hour after rTPA, with a PedNIHSS score of 7. Digital subtraction angiography was performed approximately 9 h from the onset of symptoms, showing a complete left M1 occlusion. The patient underwent successful mechanical thrombectomy and was discharged with a PedNIHSS score of 2. This case emphasizes the importance of early recognition to direct children towards rapid diagnosis and hyperacute treatment.

Wake-up stroke: From pathophysiology to management

Wake-up strokes (WUS) are strokes with unknown exact time of onset as they are noted on awakening by the patients. They represent 20% of all ischemic strokes. The chronobiological pattern of ischemic stroke onset, with higher frequency in the first morning hours, is likely to be associated with circadian fluctuations in blood pressure, heart rate, hemostatic processes, and the occurrence of atrial fibrillation episodes. The modulation of stroke onset time also involves the sleep-wake cycle as there is an increased risk associated with rapid-eye-movement sleep. Furthermore, sleep may have an impact on the expression and perception of stroke symptoms by patients, but also on brain tissue ischemia processes via a neuroprotective effect. Obstructive sleep apnea syndrome is particularly prevalent in WUS patients. Until recently, WUS was considered as a contra-indication to reperfusion therapy because of the unknown onset time and the potential cerebral bleeding risk associated with thrombolytic treatment. A renewed interest in WUS has been observed over the past few years related to an improved radiological evaluation of WUS patients and the recent demonstration of the clinical efficacy of reperfusion in selected patients when the presence of salvageable brain tissue on advanced cerebral imaging is demonstrated.

Thrombolysis with reteplase in acute pulmonary embolism

Objective

Reteplase (recombinant plasminogen activator) is a mutant of alteplase. It has a longer half-life than its parent molecule and has shown better vessel patency rates in acute myocardial infarction. In this study, we analyzed the efficacy and safety of reteplase in acute pulmonary embolism (PE).

Methods

This observational study included patients with high- and intermediate-risk acute PE, presenting within 14 days of symptom onset. The patients were treated with reteplase, which was given in two bolus doses of 10 U each, 30 min apart, along with intravenous heparin. Patients with hemodynamic compromise (high-risk or massive PE) and normotensive patients with evidence of right ventricular (RV) dysfunction (intermediate-risk or submassive PE) on echocardiography or computed tomography were included in the study. The efficacy outcomes assessed were in-hospital death and improvement of RV function by echocardiography. The safety outcomes were major bleeding, minor bleeding, and ischemic or hemorrhagic stroke during hospitalization.

Results

Of the 40 patients included, 25% were classified as high risk with hemodynamic compromise and 75% were classified as intermediate risk. RV dysfunction was present in all the patients (100%). Concomitant lower extremity deep vein thrombosis was present in 55% of the patients. The mortality rate was 5%. There was significant improvement in RV function and reduction in pulmonary artery systolic pressure and tricuspid regurgitation severity. There was no major bleeding event or stroke, and 7.5% patients had minor extracranial bleeding.

Conclusions

Double-bolus reteplase given with heparin is effective in the treatment of high- and intermediate-risk PE, with minimal risk of bleeding.

The effect of HMG-CoA reductase inhibitors on thrombolysis-induced haemorrhagic transformation

Thrombolysis-induced haemorrhagic transformation is the most challenging preventable complication in thrombolytic therapy. This condition is often associated with poor functional outcome and long-term disease burden. Statins, or 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are controversially suggested to either increase or decrease the odds of better primary outcomes compared to treatment without statins after thrombolysis in patients or animals; statins are thought to act by influencing lipid levels, the inflammatory response, blood brain barrier permeability and cell apoptosis. Statins are the cornerstone of secondary prevention of cardiovascular and cerebrovascular diseases. However, the role of statins in acute phase stroke, and the necessity of their use, remains unclear. Currently, whether statins can increase the risk of haemorrhagic transformation is of great concern for patients treated with tissue plasminogen activator (t-PA). Herein, we thoroughly summarize the recent advances that address whether the administration of statins in ischaemic stroke increases haemorrhagic transformation in patients or animals who received thrombolysis at an early stage and the related mechanisms. This review will provide more clinical and preclinical evidence to address questions regarding the exercise of caution in the use of high dose statins in patients who received thrombolysis and if low dose statins may be beneficial in decreasing thrombolysis-induced haemorrhagic transformation.

Prognostic risk factors for recurrent acute lower limb ischemia in patients treated with intra-arterial thrombolysis

OBJECTIVE

The objective of this study was to assess factors predisposing patients to recurrent acute lower limb ischemia (RALLI).

METHODS

Acute lower limb ischemia patients treated with catheter-directed thrombolysis (CDT) at Tampere University Hospital and Turku University Hospital between March 2002 and December 2015 were included. The patients' baseline demographics, comorbidities, and other characteristics were assessed retrospectively. Significant factors revealed by univariable analysis were tested in a multivariable model for associations with RALLI. A patency analysis was performed, and the risks of reocclusion were identified. The limb salvage rates after reocclusion were evaluated.

RESULTS

Altogether, 303 consecutive patients with a mean age of 71 years (standard deviation, 11.8 years) were included. Of them, 159 (52.5%) were men. A total of 164 (54.1%) native arterial and 139 (45.9%) bypass graft occlusions were initially treated with CDT. On completion of CDT, 204 additional endovascular or conventional surgical procedures on 203 patients were performed to obtain adequate distal perfusion. During a median follow-up of 40 months (interquartile range, 69 months), 40 (24.4%) cases of RALLI occurred in native arteries and 90 (64.7%) in bypass graft patients (P < .001). In native arteries, the absence of appropriate anticoagulant and antiplatelet medication was independently associated with the development of acute reocclusions (hazard ratio, 6.51) in the Cox multivariable regression analysis. The patency rates were 86.6%, 72.2%, and 68.0% at 1 year, 5 years, and 9 years, respectively. In bypass grafts, worsened tibial runoff (crural index III: hazard ratio, 2.40) was independently associated with RALLI. The respective patency rates were 60.5%, 34.0%, and 29.2% for synthetic conduits and 30.8%, 20.5%, and 13.7% for autologous vein grafts at 1 year, 5 years, and 9 years. Altogether, 38 (29.2%) major amputations were performed on patients with reocclusions. Patients with synthetic conduits demonstrated superior limb salvage rates after reocclusion in comparison to native arteries or vein grafts (P = .025).

CONCLUSIONS

Appropriate post-thrombolytic antiplatelet or anticoagulant treatment after native arterial events is of great importance, but additional data are needed to improve treatment algorithms. Adequate outflow in bypass graft patients is crucial. Patients with prosthetic bypass grafts have superior limb salvage rates after reocclusion.

Diagnostic accuracy of clinical tools for assessment of acute stroke: a systematic review

INTRODUCTION

Recanalisation therapy in acute ischaemic stroke is highly time-sensitive, and requires early identification of eligible patients to ensure better outcomes. Thus, a number of clinical assessment tools have been developed and this review examines their diagnostic capabilities.

METHODS

Diagnostic performance of currently available clinical tools for identification of acute ischaemic and haemorrhagic strokes and stroke mimicking conditions was reviewed. A systematic search of the literature published in 2015-2018 was conducted using PubMed, EMBASE, Scopus and The Cochrane Library. Prehospital and in-hospital studies with a minimum sample size of 300 patients reporting diagnostic accuracy were selected.

RESULTS

Twenty-five articles were included. Cortical signs (gaze deviation, aphasia and neglect) were shown to be significant indicators of large vessel occlusion (LVO). Sensitivity values for selecting subjects with LVO ranged from 23 to 99% whereas specificity was 24 to 97%. Clinical tools, such as FAST-ED, NIHSS, and RACE incorporating cortical signs as well as motor dysfunction demonstrated the best diagnostic accuracy. Tools for identification of stroke mimics showed sensitivity varying from 44 to 91%, and specificity of 27 to 98% with the best diagnostic performance demonstrated by FABS (90% sensitivity, 91% specificity). Hypertension and younger age predicted intracerebral haemorrhage whereas history of atrial fibrillation and diabetes were associated with ischaemia. There was a variation in approach used to establish the definitive diagnosis. Blinding of the index test assessment was not specified in about 50% of included studies.

CONCLUSIONS

A wide range of clinical assessment tools for selecting subjects with acute stroke has been developed in recent years. Assessment of both cortical and motor function using RACE, FAST-ED and NIHSS showed the best diagnostic accuracy values for selecting subjects with LVO. There were limited data on clinical tools that can be used to differentiate between acute ischaemia and haemorrhage. Diagnostic accuracy appeared to be modest for distinguishing between acute stroke and stroke mimics with optimal diagnostic performance demonstrated by the FABS tool. Further prehospital research is required to improve the diagnostic utility of clinical assessments with possible application of a two-step clinical assessment or involvement of simple brain imaging, such as transcranial ultrasonography.

Managing dysfunctional central venous access devices: a practical approach to urokinase thrombolysis

Tunnelled central venous access devices (CVADs) are defined as any intravenous multipurpose catheters placed within the central veins for use in haemodialysis and administration of blood products or chemotherapy in oncology and haematological conditions. Frequent complications include thrombosis and catheter-related infection, which may lead to significant adverse patient outcomes. Once thrombosis is suspected correction should be attempted empirically with thrombolytic agents. Commonly available thrombolytic agents in the UK include urokinase (Syner-Kinase) and alteplase (Cathflo). It is well recognised that urokinase usage differs widely and concerns were raised by clinicians about the variation of dose regimens nationally. The objective of the CVAD Focus Group was to address this issue and offer guidance in the management of suspected thrombosis of CVAD with urokinase using two algorithms for renal and non-renal dysfunctional CVAD and to audit prospectively the outcomes of intervention.

Sonothrombolysis with magnetic microbubbles under a rotational magnetic field

Thrombosis is an extremely critical clinical condition where a clot forms inside a blood vessel which blocks the blood flow through the cardiovascular system. Previous sonothrombolysis methods using ultrasound and microbubbles (MBs) often have a relatively low lysis rate due to the low microbubbles concentration at clot region caused by blood flow in the vessel. To solve this problem, the magnetic microbubbles (MMBs) that can be retained by an outer magnetic field against blood flow are used in this study. Here we report the development of a new method using the rotational magnetic field to trap and vibrate magnetic microbubbles at target clot region and then using an intravascular forward-looking ultrasound transducer to activate them acoustically. In this study, we investigated the influence of different blood flow conditions, vessel occlusion conditions (partial and fully occluded), clot ages (fresh, retracted), ultrasound parameters (input voltage, duty cycle) and rotational magnetic field parameters (amplitude, frequency) on the thrombolysis rate. The results showed that the additional use of magnetic microbubbles significantly enhances in vitro lysis of blood clot.

Tenecteplase versus alteplase in acute ischemic stroke: systematic review and meta-analysis

Tenecteplase is a product of genetic modification of recombinant tissue plasminogen activator with superior pharmacodynamic and pharmacokinetic properties. This meta-analysis was to determine whether intravenous thrombolysis with tenecteplase in patients with acute ischemic stroke has better efficacy and safety outcomes than with intravenous alteplase. PubMed, Cochrane Central Register of Controlled Trials, WHO International clinical trials registry platform (ICTRP), Australian New Zealand Clinical Trials Registry (ANZCTR), EU Clinical Trials Register (EU-CTR) and ClinicalTrials.gov were searched for trials comparing tenecteplase with alteplase in acute ischemic stroke. Functional outcomes (modified Rankin Scale at 90 days), early major neurological improvement, rates of any intracerebral haemorrhage, symptomatic intracerebral haemorrhage and mortality rate at 90 days were the outcomes compared. Four randomized controlled trials involving 1334 patients were included. The Tenecteplase group compared to the alteplase group had significantly better early major neurological improvement (RR = 1.56, 95% CI [1.00, 2.43], p = 0.05). There was no significant difference between tenecteplase and alteplase in excellent functional outcome at 90 days, good functional outcome at 90 days, any intracerebral haemorrhage, symptomatic intracerebral haemorrhage or mortality at 90 days. Our meta-analysis found tenecteplase to be significantly favouring one outcome: early major neurological improvement. Other outcomes did not differ between the tenecteplase and alteplase groups. Trials of cost-effective/benefit analysis comparing tenecteplase versus alteplase and tenecteplase versus endovascular treatment are necessary to reinforce the evidence for the potential cost advantage of tenecteplase.

Clinical outcomes of moderate to severe acute ischemic stroke in a telemedicine network

Acute ischemic strokes (AIS) with severe neurologic deficits are associated with poor short- and long-term prognosis. Thrombectomy alone or in combination with thrombolysis is used for reperfusion in patients with moderate-to-severe AIS. However, the best therapeutic approach within the setting of telemedicine networks needs to be elucidated further. The objective of this study was to analyze clinical and imaging based outcomes of moderate to severe stroke following treatment with thrombolysis, thrombectomy or a combination of both in a telemedicine network. Data of this retrospective study was abstracted from the institutional telestroke database. Patients with a National Institute of Health Stroke Scale score (NIH-SS ≥ 10) were included into the study. Primary outcome measure was the difference in NIH-SS at admission compared to discharge from the hospital. Secondary outcome measure was the discharge disposition defined as favorable (discharge to home or rehabilitation) versus unfavorable disposition (discharge to hospice/death). Furthermore, outcome was analyzed based on reperfusion status following thrombectomy using the Thrombolysis in Cerebral Infarction (TICI) scale. The NIH-SS improved in all three groups, independent of treatment subtype, with a trend towards best outcomes following thrombolysis and combined treatment therapy compared to thrombectomy alone. In addition, reperfusion rates were higher in the combination group compared to the thrombectomy only group. The number of favorable discharges was similar in all three groups. The present study stresses the benefits of tele-stroke networks in allowing to early identify and treat even patients with severe strokes and benefit from different treatment modalities.

Intravenous thrombolytic therapy for acute ischemic stroke in Hubei, China: a survey of thrombolysis rate and barriers

BACKGROUND

Rates of thrombolysis in most countries are well below best practice benchmarks. We aimed to investigate thrombolysis utilization and its associated factors in acute ischemic stroke (AIS) patients in Hubei province, China, to assess neurologists' experiences of the treatment, and to identify barriers against the treatment from perspective of AIS patients and neurologists.

METHODS

Survey of 2096 AIS patients and 709 neurologists from 66 hospitals was conducted in Hubei province between 2014 and 2015. A multivariable logistic regression model was utilized to identify the factors associated with thrombolysis utilization and neurologists' experiences with thrombolysis.

RESULTS

Of the 2096 AIS patients, only 3.8% received thrombolysis. Of the 709 neurologists, 66.0% reported using thrombolysis for AIS patients. The main reasons for not using thrombolysis were late arrival of patients, fear of the risk of complications of thrombolysis, and light or quickly recovered stroke symptoms. The behavior and clinical characteristics of patients, including early admission to hospital (odds ratio [OR] = 5.81, 95% confidence intervals [CI] 3.31-10.20), using emergency medical services to be hospitalized (OR = 3.36, 95% CI 2.00-5.62), stroke history (OR = 0.53, 95% CI 0.28-0.99), and National Institute of Health Stroke Scale score < 4 (OR = 0.46, 95% CI 0.27-0.77) were shown to significantly affect the thrombolysis utilization in the multivariate model. In addition, hospital grade (OR = 2.84, 95% CI 1.84-4.37), education level (OR = 2.49, 95% CI 1.09-5.73), and working years (OR = 1.88, 95% CI 1.18-3.00) were strongly associated with neurologists' experiences of thrombolysis.

CONCLUSIONS

A very low proportion of AIS patients received thrombolysis in Hubei province, China. Considerable education programs and interventions were required regarding knowledge of stroke treatment for clinicians and proper behavior after stroke for AIS patients and their families.

Stroke Factors Associated with Thrombolysis Use in Hospitals in Singapore and US: A Cross-Registry Comparative Study

BACKGROUND AND OBJECTIVES

This paper aims to describe and compare the characteristics of 2 stroke populations in Singapore and in St. Louis, USA, and to document thrombolysis rates and contrast factors associated with its uptake in both populations.

METHODS

The stroke populations described were from the Singapore Stroke Registry (SSR) in -Singapore and the Cognitive Rehabilitation Research Group Stroke Registry (CRRGSR) in St. Louis, MO, USA. The registries were compared in terms of demographics and stroke risk factor history. Logistic regression was used to determine factors associated with thrombolysis uptake.

RESULTS

A total of 39,323 and 8,106 episodes were recorded in SSR and CRRGSR, respectively, from 2005 to 2012. Compared to CRRGSR, patients in SSR were older, male, and from the ethnic majority. Thrombolysis rates in SSR and CRRGSR were 2.5 and 8.2%, respectively, for the study period. History of ischemic heart disease or atrial fibrillation was associated with increased uptake in both populations, while history of stroke was associated with lower uptake. For SSR, younger age and males were associated with increased uptake, while having a history of smoking or diabetes was associated with decreased uptake. For CRRGSR, ethnic minority status was associated with decreased uptake.

CONCLUSIONS

The comparison of stroke populations in Singapore and St Louis revealed distinct differences in clinicodemographics of the 2 groups. Thrombolysis uptake was driven by nonethnicity demographics in Singapore. Ethnicity was the only demographic driver of uptake in the CRRGSR population, highlighting the need to target ethnic minorities in increasing access to thrombolysis.

Thrombolysis' benefits on early post-stroke language recovery in aphasia patients

INTRODUCTION

Thrombolysis may affect ischemic stroke-related size, pattern and nature of infarcts, and has the potential to change aphasia presentation and recovery. Data on evolution of post-stroke aphasia following thrombolysis are still scarce. The aim of this study was to determine the course of language recovery through a well-validated language assessment battery after acute ischemic stroke and investigate whether traditional categorical classifications of aphasia can describe the clinical picture in post-thrombolysis phase.

MATERIALS AND METHODS

Demographic, clinical, and language assessment data of 116 patients presenting sub-acute ischemic stroke aphasia (41 treated with r-tPA; 75 non-treated) were retrospectively analyzed. The participants were assessed by a clinical neuropsychologist with a variety of subtests taken from a well-validated Italian language battery (Neuro-Psychological Aphasia Evaluation).

RESULTS

The percentage of resolved aphasia was significantly higher in treated patients compared to non-treated patients (p = 0.005) and global aphasia was more common in the non-treated group (non-treated 30.7% vs treated 17.1%). Aphasia subtypes and stroke etiologies showed no significant association, except for small vessel etiology and resolved aphasia (p = 0.041). Reperfusion treatment, baseline NIHSS, and lacunar stroke were the predictors of aphasia recovery.

CONCLUSION

The percentage of resolved aphasia was significantly higher in the treated patients compared to the non-treated, with the latter showing a higher percentage of global aphasia. Identifying classic aphasia subtypes after thrombolysis is still possible since reperfused areas do not necessary change the classification or lead to completely different aphasic syndromes. Reperfusion treatment, baseline NIHSS, and lacunar stroke were the main predictors of aphasia recovery.

Increased plasma levels of miR-124-3p, miR-125b-5p and miR-192-5p are associated with outcomes in acute ischaemic stroke patients receiving thrombolysis

BACKGROUND AND AIMS

Circulating microRNAs (miRNAs) have recently emerged as promising biomarkers for acute ischaemic stroke (AIS). However, the expression profiles of miRNAs in AIS patients receiving intravenous thrombolysis, and their associations with outcome have not been investigated.

METHODS

In a prospective cohort study, a total of 84 AIS patients, who received intravenous thrombolysis (21.4% received combined reperfusion therapy) and completed 3 month follow-up visits, were included. Favourable and unfavourable outcomes were defined as modified Rankin Scale (mRS) scores of 0-1 and 2-6, respectively. Plasma samples were collected at 24 h after thrombolysis. We used RNA sequencing to study miRNA profiles in 5 patients with unfavourable outcomes and 5 matched patients with favourable outcomes. Differentially expressed miRNAs were further validated in all cohorts using quantitative real-time polymerase chain reaction assays.

RESULTS

After identification and validation, we found that miR-124-3p, miR-125b-5p and miR-192-5p levels were higher in patients with unfavourable outcomes than in patients with favourable outcomes. Logistic regressions and receiver-operating characteristic curve analyses demonstrated that these altered miRNAs may function as predictive biomarkers for outcome in AIS patients receiving thrombolysis, whether combined with endovascular thrombectomy or not. In addition, miR-124-3p and miR-125b-5p were closely associated with stroke severity.

CONCLUSIONS

A set of circulating microRNAs (miR-124-3p, miR-125b-5p and miR-192-5p) are associated with unfavourable 3 month outcomes and might have clinical utility in AIS patients receiving thrombolysis.

Temporal Trends in Clinical Characteristics and Door-to-Needle Time in Patients Receiving Intravenous Tissue Plasminogen Activator: A Retrospective Study of 4 Hospitals in Japan

BACKGROUND

Intravenous recombinant tissue plasminogen activator (rt-PA) has become a common treatment for acute ischemic stroke and has highly time-dependent benefits. We aimed to clarify temporal trends regarding the frequency and characteristics of patients receiving rt-PA and explore factors associated with door-to-needle time (DNT) in Japanese emergency hospitals.

METHODS

Consecutive patients who received intravenous rt-PA for acute ischemic stroke from October 2005 to December 2015 were retrospectively registered from 4 hospitals. Temporal trends in the frequency and characteristics of patients receiving rt-PA and factors associated with DNT were investigated.

RESULTS

A total of 750 patients, including 688 (420 men, median 75 years old) with out-of-hospital stroke, were registered. The frequency of patients receiving intravenous rt-PA for acute ischemic stroke continuously increased from 1.8% in 2005 to 9.5% in 2015. The proportion of patients who were elderly or had prestroke disability increased over time, while pretreatment stroke severity declined. The DNT gradually decreased (median 105 minutes in 2005, 61 minutes in 2015). According to multivariate regression analysis with correction for multiple comparisons, activation of a code stroke system (standardized partial regression coefficient (β) -.50, P < .001, q < .001), onset-to-door time (β -.15, P < .001, q < .001), pretreatment with antithrombotic agents (β .12, P < .001, q = .001), and year of treatment (β .11, P = .007, q = .011) were associated with DNT.

CONCLUSIONS

Intravenous rt-PA was widely adopted in Japanese emergency hospitals. Characteristics of patients receiving intravenous rt-PA have changed over the past decade. Several factors, including the year of treatment, were associated with DNT, which has shortened over time.

[Acute deep vein thrombosis-modern diagnostics and treatment]

Acute deep pelvic vein thrombosis (DVT) is usually a non-fatal disease that causes lifelong damage. In the case of clinical suspicion of DVT, D‑dimer determination and/or imaging must be performed. If a timely diagnosis is not possible, anticoagulation should be started. The focus of treatment is the safety of the patient. All studies on thrombus-eliminating procedures, such as thrombolysis, operative open thrombectomy and endovascular revascularization, did not show any advantages over pure anticoagulation and are associated with specific risks. The minimum duration of anticoagulation is 3 months. Thereafter, the decision of prolonged anticoagulation must be made individually for each patient. Compression therapy is an integral part of the treatment of acute TVT in Germany, even the evidence for its effectivenes with respect to the prevention of post-thrombotic syndrome is low.

In vitro examination of the thrombolytic efficacy of tenecteplase and therapeutic ultrasound compared to rt-PA

Background

Optimizing thrombolytic therapy is vital for improving stroke outcomes. We aimed to develop standardized thrombolysis conditions to evaluate the efficacy of tenecteplase (TNK) compared to the current gold standard rt-PA (alteplase), with and without additional ultrasound treatment. We also wanted to introduce a new analytical approach to quantify fibrin fiber density in transmission electron microscopy (TEM).

Methods

In vitro clots that are similar to ex vivo clots concerning their histological condition and their durability were generated from whole blood. For five treatment groups we compared relative clot weight loss (each n = 60) and fibrin fiber density in TEM (each n = 5). The control group (A) was treated only with plasma. Two groups were designated for each rt-PA (B + C) and TNK (D + E). Groups C and E were additionally treated with ultrasound. Dosages were 50 μg/ml for rt-PA and 30 μg/ml for TNK. Results were evaluated by using analyses of variance (ANOVA) and post-hoc t-tests.

Results

Weight loss was increased significantly for all groups compared to the control group. Both TNK groups showed significantly increased weight loss compared to their counterpart rt-PA group (p ≤ 0.001). For TEM only group D showed significantly decreased fibrin fiber density (p < 0.05) compared to both rt-PA groups. Ultrasound did not significantly increase dissolution of clots with either method (best p = 0.16).

Conclusions

Tenecteplase dissolved clots more effectively than rt-PA with and without ultrasound. A higher sample size could provide more convincing results for TEM.

Improving the solubility, activity, and stability of reteplase using in silico design of new variants

Reteplase (recombinant plasminogen activator, r-PA) is a thrombolytic agent recombined from tissue-type plasminogen activator (t-PA), which has several prominent features such as strong thrombolytic ability and E. coli expressibility. Despite these outstanding features, it demonstrates reduced fibrin binding affinity, reduced stimulation of protease activity, and lower solubility, hence higher aggregation propensity, compared to t-PA. The present study was devoted to design r-PA variants with comparable structural stability, enhanced biological activity, and high solubility. For this purpose, computational molecular modeling techniques were utilized. The supercharging technique was applied for r-PA to designing new species of the protein. Based on the results from in silico evaluation of selected mutations in comparison to the wild-type r-PA, the designed supercharged mutant (S7 variant) exhibited augmented stability, decreased solvation energy, as well as enhanced binding affinity to fibrin. The data also implied increased plasminogen cleavage activity of the new variant. These findings have implications to therapies which involve removal of intravascular blood clots, including the treatment of acute myocardial infarction.

Multimodal CT in Acute Stroke

PURPOSE OF REVIEW

Multimodal CT imaging (non-contrast CT, NCCT; CT angiography, CTA; and CT Perfusion, CTP) is central to acute ischemic stroke diagnosis and treatment. We reviewed the purpose and interpretation of each component of multimodal CT, as well as the evidence for use in routine care.

RECENT FINDINGS

Acute stroke thrombolysis can be administered immediately following NCCT in acute ischemic stroke patients assessed within 4.5 h of symptom onset. Definitive identification of a large vessel occlusion (LVO) requires vascular imaging, which is easily achieved with CTA. This is critical, as the standard of care for LVO within 6 h of onset is now endovascular thrombectomy (EVT). CTA source images can also be used to estimate the efficacy of collateral flow in LVO patients. The final component (CTP) permits a more accurate assessment of the extent of the ischemic penumbra. Complete multimodal CT, including objective penumbral measurement with CTP, has been used to extend the EVT window to 24 h. There is also randomized controlled trial evidence for extension of the IV thrombolysis window to 9 h with multimodal CT. Although there have been attempts to assess for responders to reperfusion strategies beyond 6 h ("late window") using collateral grades, the only evidence for treatment of this group of patients is based on selection using multimodal CT including CTP. The development of fully automated software providing quantitative ischemic penumbral and core volumes has facilitated the adoption of CTP and complete multimodal CT into routine clinical use. Multimodal CT is a powerful imaging algorithm that is central to current ischemic stroke patient care.